Check valve for respirators



Gttomegcv All@ 13, 1935. H. F. sHlNDEL `CHECK VALVE FOR RESPIRATORS Filed Aug. l2, 1955 y SHNDEL 1 rwentor Patented Aug. 13,v 1935 UNITED STATES- r onEoKvALVE `Fon REsrIRA'roRs l Harry Shindel, Reading, Pa.; assigner tovWillf'l son Products, Inc., Reading; Pa., la corporation.

of Pennsylvania 'Application August 12, 1933, serial No.V 684,781

2 Claims.

This invention relates to protective equipment and more particularly to a check valve for res pirators of the type in which a flexible diaphragm l, l is provided for controlling the exhalation outlet 5 of the respirator.

In carrying out the present invention a relaltively narrow exible valve member is provided and arranged to close the exhalation outlet of the respirator by engagement with a valve seat in the form of a bead about the outlet aperture of the valve unit so that contact between the valve and its seat is along a line rather thanover a considerable portion of the surfaces of the valve and seat. And while it is recognized that the provision of a bead seat to arlord line contact with a valve member has been proposed heretofore the present invention contemplates forming the valve seat and mounting the valve on a carrier plate in such manner as to attain more efficient and reliable operation. It is also an object of the invention to protect the delicate valve member by means of a cover or guard engaging the specially formed outer end oi the valve unit.

The above mentioned and other objects and advantages of the invention will become apparent upon consideration of the following description with the accompanying drawing in which:

Figures l, 2 and 3 are perspective views illustrating, respectively,` the valve carrier plate and neck portion of the valve unit which iits in the respirator outlet, the valve member, and the valve protecting guard;

VFigure 4 is a longitudinal sectional view showing the mounting of the valve member; and

Figures 5 and 6 are fragmentary front and side Views, respectively, illustrating the check-Valve unit in conjunction with a respirator.

The check-valve unit comprises a hollow neck portion I0, iitting tightly in the exhalation outlet ll of the respirator mask I2, and a centrally apertured valve carrier plate I3, both preferably but not necessarily of metal, on which is mounted an elongated iiexible valve-member I4 of suitable material, such as thin elastic rubber, adapted to close outlet Il by being suctionally drawn against its seat as a wearer inhalesair through the filtering member I5 of the respirator, and to be readily moved off its seat on exhalation through outlet I I. To assure efficient and reliable operation and to minimize the possibility of the valve adhering to its seat, the valve member is arranged to contact its seat only along a line rather than over a considerable portion of its surface. With this end in View a bead I6 projecting slightly above the plane of the central portion of carrier I plate I3 is formed about the aperture in the plate at the inner end of neck Il).

The end portions II of carrier plate' I3 extend at an angle with respect to the plane of the central portion thereof and are provided with fastening devices I8 to which valve member I4 is attached.

The bead I5, and neck portion I@ also, are formed in the shape of an elongated ellipse so that the greater part of that portion of valve member I4 contacting bead I6 is in substantially straight line contact with the longer, nearly straight sides of the elliptical valve.

Inasmuch as valve member I4 is attached adjacent its ends to the fastening devices I8 which are located out of the plane of the central portion oi plate I3 it is normally held under slight tension exerted in the direction of the major axis of the elliptical bead in close contact with its seat.

Because of the substantially straight line contact between the edge of the valve member and the major portion of its seat the valve member forms a tight closure preventing noxious gases entering through the exhalation outlet and is extremely sensitive to the breathing of a wearer, closing tightly against its seat on very slight suction due to inhalation and readily moving ofi its seat to quickly and fully open the outlet as the wearer exhales. i

An upstanding flange 29 is provided around the edge of carrier plate I3 thus forming a protective dished enclosure within which valve memmaterial and arcuate form is provided at its ends with attaching flange 23 engageable with said end portions 2| of flange 20 so that it may be removed from the valve unit when desired by pressing it between its ends to lessen its curvature and thus disengage it. The portions 24 of iiange 20 between the undercut portions ZI may be flared outwardly, as shown in Figures 1, 5 and 6, so as to further free the easy discharge of air which the respirator wearer exhales past the raised edges of the narrow valve Hl. rIhe arcuate form of guard 22 also spaces its central portion from carrier plate I3 and this together with the narrow Valve and the outward flare of flange portions 24 provides a clear passage between the carrier plate and guard beyond the valve member.

Although an illustrative embodiment of the invention has been described in detail, there are many changes and variations which may be made without departing from the spirit of the invention and, therefore, it is desired to include all such changes and variations within the scope o1" the appended claims.

What Iclaim is:

1. A check Valve for the exhalation outlet of a respirator comprising an elongated carrier plate having a central aperture with a tubular outlet-engaging extension therefrom and a fiat flexible valve mounted on said plate and controlling said aperture; said plate having its elongated end portions angularly inclined relatively to the plane of said aperture, an upstanding peripheral edge ilange on said plate outwardly ared at such inclined ends, and an elongated arcuate guard plate spaced from said carrier plate and having end flanges engageable with the flared end anges of the latter plate by ilexing movement of said arcuate portion toward said latter plate.

2. An exhalation check valve for respirators comprising a respirator outlet-engaging tube, a Valve-carrier plate on one end of said tube, an elongated tube-communicating aperture in said plate having a beaded aperture edge forming a valve-seat, angularly bent plate extensions at the elongated ends of said opening provided with Valve-securing means, and an elongated flexible Valve having sides overlapping said beadededge seat and tensionally seated thereon by tauted bent-valve-end engagement with said securing means on said bent plate extensions.

HARRY F. SHINDEL. 

